Publication Date


Document Type


First Advisor

Zar, Jerrold H., 1941-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Pesticides--Environmental aspects; Notropis; Animal heat; Fishes--Physiology


Warm- (17 C) and cold-acclimated (8 C) young of the year, 1-year-old and 2-year-old common shiners, Notropis cornutus (Mitchill) were exposed for 24 hr to sublethal doses (1.0, 0.25 and 0.05 ppb) of the organophosphate pesticide, malathion, in an effort to determine what effect environmental concentrations of an organophosphate pesticide would have on temperature selection. All three factors studied (acclimation temperature, age and concentration) were found to affect the temperature selection response of malathion-treated N. cornutus. Malathion produced dose-dependent downward shifts in selected temperature (range of 1.91 to 4.30 C below controls) in 17 C acclimated fish but not in 8 C acclimated fish. Two-year-olds treated with 1.0 ppb displayed the greatest lowering of selected temperature followed by two-year-olds treated with 0.25 ppb. One-year-olds treated with 1.0 ppb showed a slight lowering, while no downward shifts in selected temperature were found for young of the year. Treatment with 0.05 ppb had no effect on any age group. Two-year-olds acclimated to 17 C and exposed to 1.0 ppb malathion for 24 hr were placed in clean water and allowed a recovery period. It was found that the malathion induced lowering of the selected temperature returned to control level in 24 hr.


Includes bibliographical references.||Includes illustrations.


vi, 60 pages




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